/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.everrest.core;

import org.everrest.core.impl.LifecycleComponent;

import java.util.ArrayList;
import java.util.List;

/**
 * Provide object's instance of component that support per-request lifecycle.
 *
 * @param <T>
 *         ObjectModel extensions
 * @author <a href="mailto:andrew00x@gmail.com">Andrey Parfonov</a>
 * @version $Id$
 * @see ObjectModel
 */
public class PerRequestObjectFactory<T extends ObjectModel> implements ObjectFactory<T> {
    /**
     * Object model that at least gives possibility to create object instance. Should provide full set of available
     * constructors and object fields.
     *
     * @see ObjectModel
     */
    protected final T model;

    /**
     * @param model
     *         any extension of ObjectModel
     */
    public PerRequestObjectFactory(T model) {
        this.model = model;
    }

    /** {@inheritDoc} */
    public Object getInstance(ApplicationContext context) {
        ConstructorDescriptor inj = model.getConstructorDescriptors().get(0);
        Object object = inj.createInstance(context);

        List<FieldInjector> fieldInjectors = model.getFieldInjectors();
        if (fieldInjectors != null && fieldInjectors.size() > 0) {
            for (FieldInjector injector : fieldInjectors) {
                injector.inject(object, context);
            }
        }
        doPostConstruct(object, context);
        return object;
    }

    protected final void doPostConstruct(Object object, ApplicationContext context) {
        if (context instanceof Lifecycle) {
            LifecycleComponent lc = new LifecycleComponent(object);
            lc.initialize();
            @SuppressWarnings("unchecked")
            List<LifecycleComponent> perRequest =
                    (List<LifecycleComponent>)context.getAttributes().get("org.everrest.lifecycle.PerRequest");
            if (perRequest == null) {
                perRequest = new ArrayList<LifecycleComponent>();
                context.getAttributes().put("org.everrest.lifecycle.PerRequest", perRequest);
            }
            perRequest.add(lc);
        }
    }

    /** {@inheritDoc} */
    public T getObjectModel() {
        return model;
    }
}
